News

Project Valhalla Targets JDK 28 as Java SE Expert Group Begins Work

• By John K. Waters
• June 24, 2026

The Java Community Process (JCP) approved JSR 403 during the first week of June, formally establishing the expert group responsible for developing the Java SE 28 specification.

Although the approval is largely procedural, it also marks the beginning of the next chapter in Java's evolution, one expected to be defined by the long-awaited arrival of Project Valhalla in the mainline JDK.

Valhalla, which missed the JDK 27 feature freeze earlier this month, is now targeting JDK 28 for its first preview release. The project introduces value classes, one of the most significant changes to Java's type system in years, to improve both memory efficiency and runtime performance.

The four-member expert group overseeing Java SE 28 includes Simon Ritter of Azul Systems, Iris Clark of Oracle, Stephan Herrmann of the Eclipse Foundation, and Christoph Langer of SAP SE. Clark, Oracle's OpenJDK Engineering Liaison, will serve as specification lead.

The JSR 403 schedule calls for a public review period from December 2026 through February 2027, with general availability targeted for March 2027. Early-access builds 0 and 1 were released during the same week the expert group was approved.

Why Valhalla Matters
Project Valhalla has been under development for several years and represents one of the most ambitious efforts to modernize Java's object model.

Today's Java objects carry identity, meaning every object occupies its own location in memory and is accessed through a reference. While that design has contributed to Java's flexibility and backward compatibility, it also introduces memory overhead and additional work for the garbage collector.

Valhalla introduces value classes, objects that lack identity and can therefore be stored more efficiently. Rather than allocating every instance separately on the heap, the JVM can flatten value objects directly into arrays and containing objects, reducing indirection and improving cache locality.

The result could be substantially lower memory consumption and faster execution for applications that manipulate large numbers of small objects, including financial trading systems, analytics platforms, scientific computing workloads, graphics engines, and many enterprise applications.

Unlike previous JVM optimizations, Valhalla requires language-level changes, making it one of the most technically significant Java projects since lambdas arrived in Java 8.

A Collaborative Governance Model
The approval of JSR 403 also highlights Java's collaborative development process.

Although Oracle remains specification lead, the expert group includes representatives from Azul, the Eclipse Foundation, and SAP, organizations that collectively contribute to the JVM, enterprise Java, developer tooling, and commercial OpenJDK distributions.

Beyond the expert group, the broader OpenJDK community continues to participate through mailing lists, design discussions, code reviews, testing, and bug reports.

Incremental Evolution Continues
The timing reflects Java's now-established six-month release cadence.

Rather than concentrating major changes into infrequent platform updates, OpenJDK continues to evolve through incremental releases that introduce preview and incubator features before they become permanent parts of the platform.

Valhalla exemplifies that philosophy. After years of research and experimentation, its first preview would mark the beginning of a public evaluation process rather than the completion of the project.

Other language and platform features are expected to emerge during the JDK 28 development cycle, but Valhalla is likely to remain the release's headline capability.

Looking Ahead
For enterprise developers, JSR 403 does not immediately change how Java applications are written or deployed. Instead, it signals that work has officially begun on the next release and that one of Java's most anticipated projects is once again within reach.

If JDK 27 is shaping up as a release focused on refinement, JDK 28 could become the release remembered for fundamentally changing how Java represents data in memory, potentially delivering performance improvements that developers gain with little or no application code changes.